HP-UX Trusted Computing Services A.02.00 Administrator's Guide

The TCS application level software stack is a modified version of TrouSerS. Trousers is a Common
Public License (CPL) licensed Trusted Computing Group Software Stack (TSS) that enables
multiple applications to simultaneously access and use the TPM without requiring the applications
to explicitly synchronize access. TCS complies with the TSS 1.1 Golden specification.
Architecture
Figure 1-2 illustrates the architecture of the TCS stack.
Figure 1-2 TCS Architecture
OpenSSL
Applications
TCS Daemon
TDDL -
TPM
OpenSSL
Engine
EVFS
TPM Hardware
TSPI Library
TPM
Management
Utilities
tpadmin
tpmlist
TPM RSA
Key Utility
tpmcreate
On-demand
Encryption
tpmencrypt
tpmdecrypt
TPM EVFS
Library
HP-UX TPM Device Driver
libtspi.sl
evfsvol
TSPI
Applications
libtddl.a
/dev/tpm
tcsd
/var/tpm/system.data
TCSD Persistent
Key Storage
localhost:30003
tcsd.conf
System Firmware
System Firmware
The first level of the TCS architecture stack is the system firmware that interfaces with the TPM,
which is physically attached to the system as a core I/O device. The system firmware also includes
the necessary bus logic to communicate with the TPM.
TPM Device Driver
The first layer of software consists of the HP-UX TPM device driver. This driver provides
communication between the user space software stack (the TSS Core Services tcsd daemon)
and the TPM by providing a layer for transporting a byte stream to and from the TPM.
TSS Device Driver Library
The TSS Device Driver Library (TDDL), libtddl.a, provides an interface to the TPM device
driver. This library is used only by tcsd and is not supported for customer use.
The tcsd Daemon
The TSS Core Services tcsd daemon starts at system initialization time and opens the TPM
device (/dev/tpm). After the tcsd daemon opens the TPM device, all requests to the TPM go
through the TSS stack. The tcsd daemon manages TPM resources and handles requests from
12 Trusted Computing Systems Overview